Hi Kevinn, it was just curiosity. I wanted to know if it can behave as a true mechanical mod in by-pass mode. Just tried to know all of the possibilities of this chip. That's all, my friend. By the way, if the chip has this by-pass mode, that's because this feature should be useful for someone, shouldn't it?

Makes sense. Sorry if I sounded rude. There's a user on this forum named bapgood. He has a 6400mAh 90a continous lipo battery in his custom SX350 mod. He should be able to tell you how bypass mode compares to a mechanical mod. I'm curious as well. But I'm pretty sure stacked batteries won't operate the chip at all.

@bapgood How well does your 90a lipo SX350 compare to mechanical mods when sub ohming to the point where it pulls well over 35w from the battery?

I was planing on using 2 1200 mAh lipo batteries connected together in a hammond 1590a is that going to be a problem?
Do I need to use a single cell?

Originally Posted by Onedesign1

Question 1 - Yes Link works fine after initial update including the 40W

Question 2 - Both 40W and eventually 50W will use a single 18650....note the input voltage on the specs always....this board is for single cells...so yes battery life will begin to be an issue if you cloud chase full time But its not a big issue with replaceable batts or if you're around a PC all day just plug it and let it charge...while not pass-though you can vape it while its charging. Or find a honking lipo that will fit in your box

Makes sense. Sorry if I sounded rude. There's a user on this forum named bapgood. He has a 6400mAh 90a continous lipo battery in his custom SX350 mod. He should be able to tell you how bypass mode compares to a mechanical mod. I'm curious as well. But I'm pretty sure parallel batteries won't operate the chip at all.

@bapgood How well does your 90a lipo SX350 compare to mechanical mods when sub ohming to the point where it pulls well over 35w from the battery?

Don't worry. I was just trying to get a comprehensive knowledge about the chip. By the way, when you write this: " I'm pretty sure parallel batteries won't operate the chip at all", you mean series, don't you?.

I suppose that although using batteries in series is not possible, it is possible using batteries in parallel because voltage remains under the voltage limitation (amperage would be in that case halved).

I was planing on using 2 1200 mAh lipo batteries connected together in a hammond 1590a is that going to be a problem?
Do I need to use a single cell?

I don't have any experience with dual lipos, but make sure the C rating (continues amp discharge) is above 20 if you're planning to update your chip to 40w. In my opinion, You're better off using a VTC5 battery (30 amp, 2600 mAh) for better battery life, especially above 20 watts. I used the Keystone 1042 battery holder for my VTC5 in my Hammond 1590a box. It just needed a bit of trimming with a dremel to fit perfectly. I can carry spare batteries around if I'm away from a charger for a length of time.

Since you'll be wiring in parallel, each cell should have at least a 10c rating or higher.

If your lipos have too low of a C rating you'll see some serious voltage drop at higher watts, and the chip may throw a "check battery" message.

Don't worry. I was just trying to get a comprehensive knowledge about the chip. By the way, when you write this: " I'm pretty sure parallel batteries won't operate the chip at all", you mean series, don't you?.

I suppose that although using batteries in series is not possible, it is possible using batteries in parallel because voltage remains under the voltage limitation (amperage would be in that case halved).

Yeah I meant series, fixed the post. Parallel batteries are same voltage, double capacity and output

Yeah I meant series, fixed the post. Parallel batteries are same voltage, double capacity and output

Sorry, I said amperage halved, but I was wrong. I mean, with two batteries in parallel, as you say, voltage is the same, but capacity doubles. If capacity doubles, does current double too?. For a resistance of 1 ohm and a voltage of 4.2v, the current in single battery configuration would be 4.2A. But in parallel battery configuration the current would be 8.4A. Is this ok?

Sorry, I said amperage halved, but I was wrong. I mean, with two batteries in parallel, as you say, voltage is the same, but capacity doubles. If capacity doubles, does current double too?. For a resistance of 1 ohm and a voltage of 4.2v, the current in single battery configuration would be 4.2A. But in parallel battery configuration the current would be 8.4A. Is this ok?

Thanks.

Batteries in series pushes double the current using the same ohm coil, but is more dangerous. Batteries in parallel push the same current to say a 1.8ohm coil as a single battery at 1.8 ohms. With parallel 30a VTC5 batteries, for instance, you now have 60a. You can sub ohm to under 0.1 ohms in a mechanical.

With parallel batteries, you need to build lower ohm coils, or use a chip to regulate output if you want more power

I was planing on using 2 1200 mAh lipo batteries connected together in a hammond 1590a is that going to be a problem?
Do I need to use a single cell?

The two 1200mah lipos will work fine, I am currently running the same setup. Just make sure they have a high enough c rating like was previously stated. And they need to be wired in parallel!
Here is a pic of my mod with dual lipos 2400mah total

hey guys with the Bypass mode discussion. Remember the chip can only run off 4.5V max....3.7 nominal.....thats a single cell. You cannot stack cells in series. doesn't matter Lipo, IMR, etc. In bypass it acts like a mech .... direct battery to atty but through the board...so it provides the voltages and drops for you.. But its going to limit anything to 15A as the board limit....to the best of my knowledge. But still the same single cell limit.

What we don't know is what kind of losses we get through the board vs a quality mech...it certainly doesn't seem like it could be as efficient as a quality mech. But people smarter than me can probably provide some good analysis on that.

Then again its intended for providing regulated power and the Bypass is an additional feature of the board.

@bapgood How well does your 90a lipo SX350 compare to mechanical mods when sub ohming to the point where it pulls well over 35w from the battery?

Originally Posted by Onedesign1

hey guys with the Bypass mode discussion. Remember the chip can only run off 4.5V max....3.7 nominal.....thats a single cell. You cannot stack cells in series. doesn't matter Lipo, IMR, etc. In bypass it acts like a mech .... direct battery to atty but through the board...so it provides the voltages and drops for you.. But its going to limit anything to 15A as the board limit....to the best of my knowledge. But still the same single cell limit.

What we don't know is what kind of losses we get through the board vs a quality mech...it certainly doesn't seem like it could be as efficient as a quality mech. But people smarter than me can probably provide some good analysis on that.

Then again its intended for providing regulated power and the Bypass is an additional feature of the board.

I haven't had time to test this specifically but I believe Onedesign1 is absolutely correct, that you will ultimately be governed by the 15a limit.